The influence of surcharge load on the negative skin friction on pile groups.

A series of model tests on NSF on pile groups under variety surcharge loading were designed and conducted. During the tests, pile strain, settlement of pile and soil were measured. The results indicate that when side load increases from 20kPa to 120kPa, the neutral plane of the single pile varies from 0.82 L (length of pile in sand) to 0.93 L. Pile head settlement and negative skin friction under side load were smaller compared with the results of the test under uniform loading, while the location of neutral plane was lower. [ABSTRACT FROM AUTHOR]